Open AccessIncreased sensitivity to gamma irradiation in bacteria lacking protein HU.
Author(s) -
Fatima Boubrik,
Josette RouvièreYaniv
Publication year - 1995
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.92.9.3958
Subject(s) - nucleoid , escherichia coli , biology , mutant , dna , dna replication , bacteria , cell division , dna repair , circular bacterial chromosome , microbiology and biotechnology , histone , recbcd , plasmid , cell , gene , genetics
The heterodimeric HU protein, isolated from Escherichia coli, is associated with the bacterial nucleoid and shares some properties with both histones and HMG proteins. It is the prototype of small bacterial DNA binding proteins with a pleiotropic role in the cell. HU participates in several biological processes like cell division, initiation of DNA replication, transposition, and other biochemical functions. We show here that bacteria lacking HU are extremely sensitive to gamma irradiation. Expression of either one of the subunits of HU in the hupAB double mutant nearly restores the normal survival rate. This shows that the sensitivity is due to the absence of HU rather than being the result of a secondary mutation occurring in the hupAB cells or a modification of the SOS repair system, since SOS genes are induced normally in the absence of HU. Finally, in vitro studies give an indication of its potential role: HU protects DNA against cleavage by gamma-rays.